#include <iostream>

#include "common/meshmodel.h"
#include "parameters.h"

using namespace std;
using namespace vcg;

Parameters::Parameters(bool _use_focal, Shot &_reference, int w, int h, Box &_box, CMeshO &mesh): 
  use_focal(_use_focal), max_norm(false), reference(_reference), box(_box)
{
	srand(1);
	rx = w/(double)reference.Intrinsics.ViewportPx[0];
	ry = h/(double)reference.Intrinsics.ViewportPx[1];
	pointSamples = NULL;
	initScale(mesh);
}


Parameters::Parameters(bool _use_focal, Shot &_reference, int w, int h, Box &_box):
  use_focal(_use_focal), max_norm(false), reference(_reference), box(_box)
{
	srand(1);
	rx = w/(double)reference.Intrinsics.ViewportPx[0];
	ry = h/(double)reference.Intrinsics.ViewportPx[1];
	pointSamples = NULL;
	initScale();
}


Parameters::~Parameters()
{
	/*if(pointSamples)
		delete pointSamples;*/
}

int Parameters::size()
{ 
	//number of used parameters
	if(use_focal) return 7;
	return 6;
}


double Parameters::norm()
{
	double dist = 0.0;
	for(int i = 0; i < 7; i++) 
		dist += p[i]*p[i];
	return sqrt(dist);
}


void Parameters::reset()
{
	for(int i = 0; i < 7; i++)
	{
		p[i] = 0.0;
		scale[i] = 1.0;
	}
}


double Parameters::random(double max, double min)
{
	assert(max >= min);
	double r = (double)rand() / ((double)(RAND_MAX)+(double)(1));
	return min + r*(max - min);
}


void Parameters::randomDir(int n, double *p, double len)
{
	double dist = 0.0;
	for(int i = 0; i < n; i++)
	{
		p[i] = random(1, -1);
		dist += p[i]*p[i];;
	}
	dist = len/sqrt(dist);
	for(int i = 0; i < n; i++) 
		p[i] *= dist;
}


void Parameters::rattle(double amount) 
{
	double r[7];
	randomDir(size(), r, amount);
	for(int i = 0; i < size(); i++)
		p[i] += r[i];
}


void Parameters::initScale(CMeshO &mesh)
{
	reset();
	pointSamples = new CMeshO();
	clusteringGrid.Init(mesh.bbox, 10000, mesh.bbox.Diag()*0.02f );
	clusteringGrid.AddPointSet(mesh);
	clusteringGrid.ExtractPointSet(*pointSamples);
	const double step = 0.1;
	for(int i = 0; i < size(); i++)
	{
		p[i] = step;
		Shot test = toShot(false);
		double diff = pixelDiff(test, mesh)/step;
		if(diff <= 0)
		{
			scale[i] = 1;
			cerr << "WARNING: parameter " << i << " does not change the image. " << endl;
		} 
		else
			scale[i] = 1/diff;
		p[i] = 0.0;
	}
	
}


void Parameters::initScale()
{
	reset();
	for(int i = 0; i < size(); i++)
	{
		p[i] = 1.0;
		Shot test = toShot(false);
		scale[i] = 1/pixelDiff(test);
		p[i] = 0.0;
	}
}


double Parameters::pixelDiff(CMeshO &mesh)
{
	Shot s = toShot();
	return pixelDiff(s, mesh);
}


double Parameters::pixelDiff(Shot &test, CMeshO &mesh)
{
	double maxdist = 0.0;
	double avedist = 0.0;
	int count = 0;
	CMeshO::VertexIterator vi;
	for(vi = pointSamples->vert.begin(); vi != pointSamples->vert.end(); ++vi ) 
	{
   		vcg::Point3f c;
		c.Import((*vi).P());
		Point2f diff = pixelDiff(test, c);
		double dd = diff.Norm();
		if(dd <= 0) continue; //outside of viewpoint
		if(dd > maxdist) maxdist = dd;
		avedist += dd*dd;
		count++;
    }
	//for(int i = 0; i < nsamples; i++)
	//{
	//	double r = (double)rand() / ((double)(RAND_MAX)+(double)(1));
	//	double g = (double)rand() / ((double)(RAND_MAX)+(double)(1));
	//	r = r*16000*16000+g*16000;
	//	int v = ((int)r)%(mesh.vert.size());
	//	vcg::Point3d c;
	//	c.Import(mesh.vert[v].P());
	//	Point2d diff = pixelDiff(test, c);
	//	double dd = diff.Norm();
	//	if(dd <= 0) continue; //outside of viewpoint
	//	if(dd > maxdist) maxdist = dd;
	//	avedist += dd*dd;
	//	count++;
	//}
	if(max_norm) return maxdist;
	return sqrt(avedist/count);
}


double Parameters::pixelDiff()
{
	Shot s = toShot();
	return pixelDiff(s);
}


double Parameters::pixelDiff(Shot &test)
{
	double maxdist = 0.0;
	double avedist = 0.0;

	for(int i = 0; i < 8; i++)
	{
		double dd = pixelDiff(test, box.P(i)).Norm();
		if(dd < 0) continue; //outside of viewpoint
		if(dd > maxdist) maxdist = dd;
		avedist += dd*dd;
	}
	if(max_norm) return maxdist;
	return sqrt(avedist/8);
}


vcg::Point2f Parameters::pixelDiff(Shot &test, vcg::Point3f p)
{
  vcg::Point2f before = reference.Project(p)*rx;
  if(before[0] < 0 || before[0] > reference.Intrinsics.ViewportPx[0] || before[1] < 0 || before[1] > reference.Intrinsics.ViewportPx[1])
	  return vcg::Point2f(0, 0);
  vcg::Point2f after = test.Project(p)*rx;
  return (after - before);
}


vcg::Shot<float> Parameters::toShot(bool scale)
{
	double _p[7];
	scramble(_p, scale);

	Similarity<float, Matrix44<float> > s;
	s.SetIdentity();
	s.rot.FromEulerAngles(_p[3], _p[4], _p[5]);
	s.tra = vcg::Point3f(_p[0], _p[1], _p[2]);

	Shot shot = reference;
	if(use_focal)
	{
		double fov = reference.Intrinsics.FocalMm;  
		double h = reference.Intrinsics.ViewportPx[0]*reference.Intrinsics.PixelSizeMm[0];
		//double f = h/fov;
		//f += _p[6]/100;
		//shot.Intrinsics.FocalMm = h/f;

		//double newfov = fov*exp(0.1*_p[6]);
		double newfov = fov + _p[6];
		shot.Intrinsics.FocalMm = newfov;
		if(shot.Intrinsics.FocalMm <= 1) shot.Intrinsics.FocalMm = 1;
	}
	else
		shot.Intrinsics.FocalMm = reference.Intrinsics.FocalMm;
	Matrix44f rot = shot.Extrinsics.Rot();
	Matrix44f irot = Inverse(rot);

	Point3f tra = shot.Extrinsics.Tra();

	//rotation in camera space, remove it and we are in model space
	s.rot = irot*s.rot*rot;

	Matrix44f isrot = Inverse(s.rot);
	Point3f center = box.Center();

	shot.Extrinsics.SetRot(rot *s.rot);
	shot.Extrinsics.SetTra(irot*s.tra + isrot*(tra - center)  + center);

	return shot;
}


void Parameters::scramble(double *_p, bool rescale)
{
	if(rescale)
	{
		for (int i = 0; i < size(); i++)
			_p[i] = p[i]*scale[i];
	} 
	else
	{
		for (int i = 0; i < size(); i++)
			_p[i] = p[i];
	} 
	if(use_focal)
	{
		Point3f center = box.Center();
		//initial distance to the center of the object
		double dist = (center - reference.Extrinsics.Tra()).Norm();
		//initial fov
		double fov = reference.Intrinsics.FocalMm;
		double h = reference.Intrinsics.ViewportPx[0]*reference.Intrinsics.PixelSizeMm[0];

		/*double f = h/fov;
		f += _p[6]/100;
		double newfov = h/f;*/
		//double newfov = fov*exp(0.1*_p[6]);
		double newfov = fov + _p[6];
		double ratio = (newfov - fov)/fov;

		Point3f fcenter = reference.ConvertWorldToCameraCoordinates(center);
		fcenter[0] = 0; fcenter[1] = 0;
		fcenter = reference.ConvertCameraToWorldCoordinates(fcenter);

		Point3f view = reference.Extrinsics.Tra();
		//view = center + (view - center)*ratio;
		Point3f diff = view - (center + (view - center)*ratio);

		_p[2] += ratio*dist; 

		/*    double z = (_p[2] + _p[6])/2;
		double f = (_p[2] - _p[6])/2;
		_p[2] = z;
		_p[6] = f; */
	}
}

